Optical pickup device, recorder and/or reproducer

Abstract

An optical system and pick-up device having an optical magnification suitable for three different optical disc formats and a light emitting means for emitting a laser beam having a wavelength corresponding to each disc in the optical system of the optical pickup for recording and / or reproducing an information signal to the optical discs. The optical pickup device has a first light emitting unit for emitting a laser beam having a first wavelength or a second wavelength, a second light emitting unit for emitting a laser beam having a third wavelength, a first collimator lens for transmitting the laser beams having the first or second wavelengths, a second collimator lens for transmitting the laser beam having the third wavelength, a first objective lens for transmitting the laser beams having the first or third wavelengths, and a second objective lens for transmitting the laser beam having the second wavelength.

Description

CROSS REFERENCES TO RELATED APPLICATIONS[0001]The present invention contains subject matter related to Japanese Patent Application JP 2004-203814 filed in the Japanese Patent Office on Jul. 9, 2004, the entire contents of which being incorporated herein by reference.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to an optical pickup device corresponding to an optical disc of at least three formats. The present invention particularly relates to an optical pickup device having a 2-wavelength laser element and a 1-wavelength laser element, and a collimating means having different refractive powers of two systems and an objective lens having two different focal lengths, and a recorder and / or reproducer using the same.[0004]2. Description of Related Art[0005]There is, heretofore, an optical pickup device for recording and / or reproducing an information signal to an optical disc having different formats, such as a CD (Compact Disc) and a DVD (...

AI Technical Summary

Benefits of technology

[0015]Accordingly, it is desirable to provide an optical pickup device which realizes an optical system having an optical magnification suitable for each disc format between three optical discs and a light emitting means for emitting a laser beam having a wavelength corresponding to each disc in the optical system of the optical pickup for recording and / or reproducing an information signal to the optical discs and which prevents the number of components from being increased to simplify the composition of the optical system, thereby preventing the length of an optical path from being lengthened, the optical pickup from being increased in size.

[0019]According to the optical pickup device and the recorder and / or reproducer, the optical path having optimum magnifications to the first to the third laser beams emitted corresponding to the three optical discs having different formats can be formed by using the two light emitting units and the collimator lenses and two objective lenses. Therefore, the optical paths corresponding to the laser beams of the respective wavelengths can be commonly used, and the optical system having the optical magnifications suitable for the respective optical disc formats can be realized between the light emitting units for emitting the laser beam having the wavelengths corresponding to the respective optical discs and the respective optical discs without introducing the maximizing of the optical path of the pickup optical system.

Problems solved by technology

As a result, the quantity of light on the signal recording surface of the disc becomes insufficient.

Accordingly, when one lens system for realizing the optical magnification suitable for the three disc formats is composed, the number of components for constituting the optical system is increased, and its construction is complicated.

Therefore, this optical system cannot respond to the requests of shortening the optical path of the pickup optical system and a size reduction of the pickup device, etc.

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